Urine composition in type 2 diabetes: predisposition to uric acid nephrolithiasis.

Type 2 diabetes is a risk factor for nephrolithiasis in general and has been associated with uric acid stones in particular. The purpose of this study was to identify the metabolic features that place patients with type 2 diabetes at increased risk for uric acid nephrolithiasis. Three groups of individuals were recruited for this outpatient study: patients who have type 2 diabetes and are not stone formers (n = 24), patients who do not have diabetes and are uric acid stone formers (UASF; n = 8), and normal volunteers (NV; n = 59). Participants provided a fasting blood sample and a single 24-h urine collection for stone risk analysis. Twenty-four-hour urine volume and total uric acid did not differ among the three groups. Patients with type 2 diabetes and UASF had lower 24-h urine pH than NV. Urine pH inversely correlated with both body weight and 24-h urine sulfate in all groups. Urine pH remained significantly lower in patients with type 2 diabetes and UASF than NV after adjustment for weight and urine sulfate (P < 0.01). For a given urine sulfate, urine net acid excretion tended to be higher in patients with type 2 diabetes versus NV. With increasing urine sulfate, NV and patients with type 2 diabetes had a similar rise in urine ammonium, whereas in UASF, ammonium excretion remained unchanged. The main risk factor for uric acid nephrolithiasis in patients with type 2 diabetes is a low urine pH. Higher body mass and increased acid intake can contribute to but cannot entirely account for the lower urine pH in patients with type 2 diabetes.

[1]  M. Stampfer,et al.  Diabetes mellitus and the risk of nephrolithiasis. , 2005, Kidney international.

[2]  M. Stampfer,et al.  Obesity, weight gain, and the risk of kidney stones. , 2005, JAMA.

[3]  J. Torras,et al.  High prevalence of uric acid calculi in diabetic stone formers , 2005 .

[4]  K. Flegal,et al.  Prevalence of overweight and obesity among US children, adolescents, and adults, 1999-2002. , 2004, JAMA.

[5]  B. Adams-Huet,et al.  Association of urinary pH with body weight in nephrolithiasis. , 2004, Kidney international.

[6]  O. Moe,et al.  Novel insights into the pathogenesis of uric acid nephrolithiasis , 2004, Current opinion in nephrology and hypertension.

[7]  N. Abate,et al.  The metabolic syndrome and uric acid nephrolithiasis: novel features of renal manifestation of insulin resistance. , 2004, Kidney international.

[8]  M. Pirastu,et al.  Urinary glycosaminoglycans as risk factors for uric acid nephrolithiasis: case control study in a Sardinian genetic isolate. , 2003, Urology.

[9]  G. Preminger,et al.  Biochemical profile of stone-forming patients with diabetes mellitus. , 2003, Urology.

[10]  B. Adams-Huet,et al.  Pathophysiologic basis for normouricosuric uric acid nephrolithiasis. , 2002, Kidney international.

[11]  W. Frawley,et al.  Biochemical profile of idiopathic uric acid nephrolithiasis. , 2001, Kidney international.

[12]  J. Lieske,et al.  Adhesion of uric acid crystals to the surface of renal epithelial cells. , 2000, American journal of physiology. Renal physiology.

[13]  H. King,et al.  Global Burden of Diabetes, 1995–2025: Prevalence, numerical estimates, and projections , 1998, Diabetes Care.

[14]  G. Reaven,et al.  Plasma lactate concentration in obesity and type 2 diabetes. , 1993, Diabete & metabolisme.

[15]  M. Oh.  A new method for estimating G-I absorption of alkali. , 1989, Kidney international.

[16]  V. Teplan,et al.  Acidification capacity of the kidneys and aging. , 1989, Physiologia Bohemoslovaca.

[17]  Y. Matsuzawa,et al.  Contribution of intra-abdominal fat accumulation to the impairment of glucose and lipid metabolism in human obesity. , 1987, Metabolism: clinical and experimental.

[18]  A. Hesse,et al.  Dependence of urine composition on the age and sex of healthy subjects. , 1986, Clinica chimica acta; international journal of clinical chemistry.

[19]  A. Francendese,et al.  Lactate Release from Isolated Rat Adipocytes: Influence of Cell Size, Glucose Concentration, Insulin and Epinephrine , 1983, Hormone and metabolic research = Hormon- und Stoffwechselforschung = Hormones et metabolisme.

[20]  B. Agarwal,et al.  Renal acidification in elderly subjects. , 1980, Nephron.

[21]  B. Finlayson,et al.  Stability of first dissociable proton of uric acid , 1974 .

[22]  J. Campbell,et al.  Relationship of Dietary Intake of Sulphur Amino-acids to Urinary Excretion of Inorganic Sulphate in Man , 1965, Nature.